The present invention relates to a fastening member to be employed for connecting boards such as siding boards to each other.
Recently, a large number of decorative siding boards having various surface patterns and designs are now put on the market in order to meet the consumer's demands for a more sophisticatedly designed external wall of housing.
In related arts, conventionally, the decorative siding boards are attached, via a underlayment using screws or nails, to the external wall of housing with the longitudinal direction of the siding boards being orientated in the horizontal or vertical direction. However, when the decorative siding boards are fastened using screws or nails, the decorative surface of the decorative siding boards may be damaged due to the screws or nails, thereby spoiling the decorative design of the siding boards.
In a prior art, with a view to overcome the aforementioned problems, a fastening member 30 as shown in FIG. 7 has been proposed as a fastening member for the horizontal installing of the siding boards (for example, Japanese Patent Unexamined Publication H9-203184). This fastening member 30 comprises a substrate 31, a horizontal portion 32 perpendicularly projected from the substrate 31, an upwardly inclined hook portion 33A obliquely extended upward from the distal edge of the horizontal portion 32, and a downwardly inclined hook portion 33B obliquely extended downward from the distal edge of the horizontal portion 32.
As shown in FIG. 8, a large number of the fastening members 30 (metallic fastening members) are adapted to be arrayed horizontally and fixed to a backing member 61 such as corner posts and studs by making use of screws 62 which are to be applied through vis holes 34 formed in the substrate 31. In this case, the siding boards 40A and 40B are respectively formed of a laterally elongated shape, four sides of which are respectively formed into a shiplap configuration. Specifically, the upper side and one lateral side of these siding boards 40A and 40B are respectively formed into an underlying rabbeted portion, while the lower side and the other lateral side these siding boards 40A and 40B are respectively formed into an overlying rabbeted portion. In the embodiment shown in FIG. 8, the lower side of the upper siding board 40A to be joined is formed into an overlying rabbeted portion, while the upper side of the lower siding board 40B is formed into an underlying rabbeted portion. The overlying rabbeted portion is consisted of a overlying tongue patterning portion 41 constituting the front side of the overlying rabbeted portion, an overlying tongue engaging portion 42 constituting the back side of the overlying rabbeted portion, and a groove portion 43 formed between the overlying tongue patterning portion 41 and the overlying tongue engaging portion 42. On the other hand, the underlying rabbeted portion is consisted of an underlying tongue engaging portion 44 constituting the back side of the underlying rabbeted portion and adapted to face the overlying tongue engaging portion 42.
The installation of the siding boards 40A and 40B can be performed as follows. First of all, the distal edge portion of the underlying tongue engaging portion 44 of a lower siding board 40B is fitted in the lower engaging portion 50B (which is formed with a substrate 31, a horizontal portion 32 and a downwardly inclined hook portion 33B) of the metallic fastening member 30 which has been attached in advance to the backing member 61, thereby securing the lower siding board 40B in a lateral state to the backing member 61.
Then, the overlying tongue engaging portion 42 of an upper siding board 40A is fitted in the upper engaging portion 50A (which is formed with a substrate 31, a horizontal portion 32 and an upwardly inclined hook portion 33A) of the metallic fastening member 30, thereby securing the upper siding board 40A to the underlayment 61. Since the upper siding board 40A and the lower siding board 40B are connected in this manner, there is little possibility that the surfaces of these siding boards are damaged as in the case of fastening with screws or vises, and at the same time, the existence of the metallic fastening member 30 cannot be externally recognized, thus making it possible to provide a very preferable external appearance of board siding.
By the way, FIG. 9 shows a siding board 40 as viewed from the front surface side thereof (the side to which a design is applied), the siding board 40 being provided with underlying rabbeted portions 44A,44B at the top side and right side thereof and with overlying rabbeted portions 41A, 41B at the bottom side and left side thereof. More specifically, an underlying rabbeted portion 44A is formed horizontally at the top side of the siding board 40, while an underlying rabbeted portion 44B is formed perpendicularly at the right side of the siding board 40. A caulking agent 45A or 45B is coated on a front surface portion of each of the underlying rabbeted portions 44A and 44B, which is spaced apart by a predetermined distance from the inner corner portion of each of the underlying tongue engaging portions 44A and 44B. This caulking agent may be applied also to a back surface portion of each of the horizontally extending overlying tongue patterning portion 41A and the vertically extending overlying tongue patterning portion 41B (which constitute the bottom side and left side of the siding board 40, respectively), which is spaced apart by a predetermined distance from the inner corner portion of each of the overlying tongue patterning portions 41A and 41B.
FIG. 10 is a perspective view illustrating partially a connected state of siding boards which are piled in the vertical direction. In this case, the overlying rabbeted portion formed at the bottom side of the upper siding board 40A is fittingly connected with the underlying rabbeted portion formed at the top side of the lower siding board 40B. At this occasion, a gap S is formed at the connected portion between these siding boards 40A and 40B. Further, a number of the siding boards are designed to be laterally placed on both sides (right and left sides) of the these siding boards 40A and 40B. In this case, the overlying rabbeted portion formed at the left side of the siding board is fittingly connected with the underlying rabbeted portion formed at the right side of the upper siding board 40A (and of the lower siding board 40B). On this occasion, a gap S2 is also formed at the connected portion between these siding boards. As seen from FIG. 10, the gap S1 extending horizontally becomes contiguous with the gap S2 extending vertically.
There is a possibility that rain water may leak into these gaps S1 and S2. Since the caulking agent 45A applied to the front surface portion of the underlying rabbeted portion 44A of the top side of the lower siding board 40B is caused to contact with the back surface of the overlying tongue patterning portion 41A of the bottom side of the upper siding board 40A so as to form a sealing portion, it is possible to prevent the rain water that has been entered into the horizontal gap S1 from slipping vertically into the back surface side of the siding board 40A and 40B. Likewise, it is also possible to prevent the rain water that has been entered into the vertical gap S2 from slipping laterally into the back surface side of the siding board 40A and 40B.
On the other hand, the rain water that has been entered into the horizontal gap S1 is caused to move horizontally to reach the vertical gap S2 and to flow downward through this vertical gap S2. By the way, as shown in FIG. 8, although the metallic fastening member 30 is disposed at the junction between the siding boards 40A and 40B, since the inner surface of the upwardly inclined hook portion 33A of the metallic fastening member 30 is closely contacted with the inclined surface of the overlying tongue engaging portion 42 of the upper siding board 40A, there is little possibility that the rain water flowing downward through the vertically extending gap S2 may slip or leak into the interior of the upper engaging portion 50A (a trace amount even if there is any leakage), so that the rain water is possibly caused to flow downward after passing over the top side of the upwardly inclined hook portion 33A, thereby allowing the rain water to enter into the space Sa having a triangular cross-section, which is encircled by the front surface of the upwardly inclined hook portion 33A, the front surface of the downwardly inclined hook portion 33B and the back surface of the overlying tongue patterning portion 41 of the upper siding board 40A.
As mentioned above, since a seal portion is formed between the back surface of the overlying tongue patterning portion 41 A of the bottom side of the upper siding board 40A and the front surface of the underlying tongue-attached portion 44A of the upper side of the lower siding board 40B, the rain water that has been entered into the space Sa having a triangular cross-section as mentioned above is caused to temporarily retain inside the space Sa without immediately flowing downward from the space Sa. The rain water retaining inside the space Sa is caused to move right and left, and then leaks out from the side edges of the hook portions 33A and 33B, thereby causing the rain water to flow into a space which is formed higher than the caulking agent 45A that has been applied horizontally to the front surface of the underlying tongue-attached portion 44A of the upper side of the lower siding board 40B. Likewise, the rain water that has been leaked into the upper engaging portion 50A is also caused to leak out from the side edges of the hook portions 33A and 33B or of the horizontal portion 32, thereby causing the rain water to flow into the aforementioned space. Since this space is communicated with the back side of the siding boards 40A and 40B, the rain water leaked into the space is allowed to enter into the back side of the siding boards 40A and 40B, thus damaging the siding boards.